Surface water-groundwater interactions drive the spatial variability of dissolved heavy metals and interfacial fluxes in mangrove intertidal zones

Li，Zhenyang1,3; Xiao，Kai2,3; Li，Yasong4; Pan，Feng5; Li，Hailong2; Zheng，Yan2; Zheng，Chunmiao2; Liu，Yan2

2024-03-01

10.1016/j.jhydrol.2024.130884

Journal of Hydrology   影响因子和分区

0022-1694

The intertidal aquifer is a crucial area that significantly influences the transport of heavy metals and the health of coastal environment. In this study, we used a 3-dimensional sampling method to analyze the spatial variability of heavy metals in the groundwater of the mangrove intertidal zone in China. The pollution level of heavy metals and their release processes into coastal waters through groundwater discharge were also explored. Our findings revealed high spatial heterogeneity of heavy metals occurred along the cross-shore, parallel-shore, and depth directions. Specifically, heavy metals exhibited inconsistent variation trends between the seawater infiltrated zone and groundwater discharge zone along the cross-shore direction. Fe, Cr, Cu, Zn, and Pb exhibited a similar variation trend along the cross-shore direction, but were opposite to that of Hg and As. In addition, most heavy metals showed higher concentrations in mangrove groundwater compared to inland pond water and coastal seawater, indicating that mangrove intertidal zone played a crucial role in sequestering heavy metals. The spatial variability of heavy metals can be attributed to different exchange types and magnitudes between the surface water and groundwater, as well as the complex biogeochemical reactions. Our study also identified a slight pollution level of Zn and Hg, and high groundwater discharge-derived fluxes of Hg and As compared with other study sites in the world. In addition, this study highlights the importance of considering different groundwater end-member, especially for redox sensitive heavy metals, when determining groundwater discharge-derived fluxes into the surface water in mangrove intertidal zone.

Groundwater Heavy metal fluxes Intertidal zone Mangrove Spatial variability

SCI ; EI

英语

通讯

ENGINEERING

2-s2.0-85186121420

Scopus

1.Hebei Institute of Water Science,Shijiazhuang,050051,China
2.State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control,School of Environmental Science and Engineering,Southern University of Science and Technology,Shenzhen,Guangdong,518055,China
3.CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation,Yantai Institute of Coastal Zone Research,Chinese Academy of Sciences,Yantai,264003,China
4.Fujian Provincial Key Laboratory of Water Cycling and Eco-Geological Processes,Xiamen,361021,China
5.Fuiian Key Laboratory of Coastal Pollution Prevention and Control,College of the Environment & Ecology,Xiamen University,Xiamen,361102,China

Li，Zhenyang,Xiao，Kai,Li，Yasong,et al. Surface water-groundwater interactions drive the spatial variability of dissolved heavy metals and interfacial fluxes in mangrove intertidal zones[J]. Journal of Hydrology,2024,632.

Li，Zhenyang.,Xiao，Kai.,Li，Yasong.,Pan，Feng.,Li，Hailong.,...&Liu，Yan.(2024).Surface water-groundwater interactions drive the spatial variability of dissolved heavy metals and interfacial fluxes in mangrove intertidal zones.Journal of Hydrology,632.

Li，Zhenyang,et al."Surface water-groundwater interactions drive the spatial variability of dissolved heavy metals and interfacial fluxes in mangrove intertidal zones".Journal of Hydrology 632(2024).